Two Russian nationals have been named over the novichok poisoning of Sergei and Yulia Skripal in Salisbury, Wiltshire.

Skripal, a former Russian spy, and his daughter Yulia were found last June slumped on a bench in Salisbury but both survived the attack after being critically ill for several months.

On 30 June 2018 a similar poisoning of two British nationals in Amesbury, seven miles from Salisbury, involved the same nerve agent. A man found the nerve agent in a perfume bottle and gave it to a woman who sprayed it on her wrist. The woman, Dawn Sturgess, fell ill within 15 minutes and died on 8 July, but the man who also came into contact with the poison, survived.

The two Russian suspects, Petrov and Boshirov were not linked to this separate attack.

They were however charged with the use and possession of the nerve agent novichok, banned under the Chemical Weapons Act and also charged with the conspiracy to murder the Skripals as well as the causing of grievous bodily harm with intent.

The investigation by the CPS recovered CCTV footage of the two Russian nationals after they flew into Gatwick airport on an Aeroflot flight on the 2 March and stayed in the City Stay hotel in east London. They visited Salisbury that Saturday in what police said they were satisfied was a reconnaissance trip.

They returned to Salisbury on Sunday. Police revealed that CCTV showed them in the vicinity of the Skripal house. The police believe that the front door was contaminated by the nerve agent, following which the suspects returned to Heathrow airport and flew back home. Health experts said that nobody who was travelling with the suspects via train and London underground is at risk and no one reported falling ill.

Sue Hemming, the CPS director of legal services, said: “Prosecutors from CPS counter-terrorism division have considered the evidence and have concluded there is sufficient evidence to provide a realistic prospect of conviction and it is clearly in the public interest to charge Alexander Petrov and Ruslan Boshirov, who are Russian nationals.”

She continued by saying that it is up to the jury to decide whether the evidence is enough for the suspects to be sentenced. “We will not be applying to Russia for the extradition of these men as the Russian constitution does not permit extradition of its own nationals. Russia has made this clear following requests for extradition in other cases. Should this position change then an extradition request would be made," Hemming said.

The CPS said that they have however obtained a European arrest warrant (EAW) which means that if either suspect travels to a country where the EAW is valid, they would be arrested and forced to face extradition on the charges against them.

Wiltshire’s chief constable, Kier Pritchard, said: “I welcome the significant news today from the counter-terrorism policing network regarding the identification of two suspects who are believed to be responsible for the attempted murders of Sergei and Yulia Skripal. Furthermore, I also welcome the news from the CPS that sufficient evidence has been secured to bring significant charges against these two individuals."

He reassured the public of Salisbury and Amesbury that the authorities would continue to work closely to manage the impact of this incidient. "We remain very grateful for the support of the public throughout what has been the most challenging of times."

Meanwhile, Prime minister Theresa May told parliament that the two suspects had clear orders from Moscow. "The two individuals named by the police and CPS are officers from the Russian military intelligence service, also known as the GRU."

She said that the GRU is a highly disciplined organisation with a well-established chain of command and that Petrov's and Boshirov's mission was likely approved at a senior level of the Russian state.

May promised new action to combat the GRU and Russia more effectively.